Exercise as cancer treatment: A clinical oncology framework for exercise oncology research

Exercise boost after surgery improves survival in model of metastatic breast cancer

Introduction

Despite advances in breast cancer diagnosis and treatment of the primary tumor, metastatic breast cancer tumors remain largely incurable, and their growth is responsible for the majority of breast cancer-related deaths. There is therefore a critical need to identify ways to reduce metastatic tumor burden and increase breast cancer patient survival. While surgery and pharmacological treatments are the cornerstones of breast cancer intervention, epidemiological data suggests that physical activity can lower the risk of breast cancer development, improve adjuvant treatment tolerance, reduce the risk of disease recurrence and lower breast cancer-related death.

Methods

In this preclinical study, we set out to examine the impact of exercise on metastatic development in triple negative breast cancer (TNBC), using different 4T1 metastasis models, voluntary wheel running and surgical interventions. Tumors were analyzed for hypoxia and immune cell infiltration.

Results

Voluntary wheel running was observed to significantly increase metastasis-free survival, doubling the median survival time. However, these improvements were only observed when a boost in physical exercise occurred following surgery. To investigate this, we performed mock surgeries and confirmed surgical stress was needed to enable the positive effects of the boost in exercise on reducing metastatic tumor burden in mice with either spontaneous metastasis or experimentally-induced metastasis. These changes occurred in the absence of alterations in tumor growth, hypoxia and immune cell infiltration.

Discussion

Taken together, our results suggest that having a boost of physical activity following surgery may be beneficial to delay breast cancer metastatic development.

Effect of low- and moderate-intensity endurance exercise on physical functioning among breast cancer survivors: a randomized controlled trial

PURPOSE

Compare the effects of low-intensity and moderate-intensity exercise on physical functioning in breast cancer survivors.

METHODS

Women aged 50 + years and post-primary treatment for stage 0 to III breast cancer were randomly assigned to a 6-month low-intensity (LIG) or moderate-intensity (MIG) exercise group. Participants were instructed to walk (low- or moderate-intensity) for 30 min five days a week, followed by flexibility exercises, and do strengthening and balance exercises twice weekly. Exercise adherence was facilitated with seven individual counseling sessions tapered over six months and a Theory of Planned Behavior-based booklet. Assessments occurred at baseline, 6 months (post-intervention), and 12 months. Primary measures were PROMIS Physical Functioning, PROMIS Global Health, and six-minute walk test (6MWT).

RESULTS

Of 101 women randomized, 65 (64.4%) completed the study. No statistically significant between-group differences occurred at post-intervention or 12 months. Compared to baseline, within-group improvements in PROMIS physical functioning occurred (LIG increased from 45.87 ± 7.58 to 48.37 ± 7.13 post-intervention (p = 0.01); MIG increased from 45.26 ± 7.27 to 49.53 ± 8.80 post-intervention (p = 0.002) and 48.91 ± 9.29 at 12 months (p = 0.02)). Similarly, Global Health physical health improved (LIG increased from 46.04 ± 5.00 to 49.19 ± 5.76 post-intervention (p = 0.001); MIG increased from 45.06 ± 6.59 to 48.20 ± 7.33 post-intervention (p = 0.005) and 48.49 ± 7.89 at 12 months (p = 0.007)). 6MWT improved between post-intervention and 12 months for the LIG (469.99 ± 64.69 m to 492.19 ± 68.64 m, p = 0.008) and between baseline and post-intervention for the MIG (471.01 ± 62.69 m to 495.88 ± 66.64 m, p = 0.006).

CONCLUSION

Both low and moderate-intensity exercise led to significant improvement in physical functioning. When feasible and acceptable, prescribing low-intensity exercise can yield important benefits.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT02982564.

The potential role of exercise in mitigating fertility toxicity associated with immune checkpoint inhibitors (ICIs) in cancer patients

Over the last decade, therapeutic advances in cancer immunotherapy have rapidly progressed, leading to an expansion of clinical trials and the development of novel immune checkpoint inhibitors (ICIs) and combination treatments. While ICIs offer substantial clinical benefits, they are also associated with various side effects, notably concerning endocrine function and potential gonadal damage following the initiation of immunotherapy. Exercise has demonstrated promise in enhancing treatment efficacy, including symptom reduction in cancer patients. Research has also established the benefits of exercise in managing fertility and reproductive health. However, there is limited data on the effectiveness of exercise in mitigating fertility-related side effects specifically in patients undergoing ICIs therapy. Given that a significant number of cancer patients are of reproductive age, it is crucial to address potential sexual side effects and offer fertility preservation options. Ensuring that patients are well-informed and supported in their reproductive health decisions is vital. This review reports the prevalence of immune-related adverse effects linked to fertility in cancer patients undergoing ICIs, explores the potential mechanisms by which ICIs may impact reproductive health, and emphasizes the role of exercise in mitigating these adverse effects.

The Physical Activity and Cancer Control (PACC) framework: update on the evidence, guidelines, and future research priorities

BACKGROUND

We proposed the Physical Activity and Cancer Control (PACC) framework in 2007 to help organise, focus, and stimulate research on physical activity in eight cancer control categories: prevention, detection, treatment preparation/coping, treatment coping/effectiveness, recovery/rehabilitation, disease prevention/health promotion, palliation, and survival.

METHODS

This perspective paper provides a high-level overview of the scientific advances in physical activity research across cancer control categories, summarises current guidelines, updates the PACC framework, identifies remaining and emerging knowledge gaps, and provides future research directions.

RESULTS

Many scientific advances have been made that are reflected in updated physical activity guidelines for six of the cancer control categories apart from detection and palliation. Nevertheless, the minimal and optimal type, dose, and timing of physical activity across cancer control categories remain unknown, especially for the understudied population subgroups defined by cancer type, age, race/ethnicity, and resource level of regions/countries.

CONCLUSION

To achieve the full benefit of physical activity in cancer control, future research should use innovative study designs that include diverse at-risk populations and understudied cancer sites. Additionally, effective behaviour change strategies are needed to increase physical activity levels across populations that use implementation science to accelerate the translation from evidence generation into practical, real-world interventions.

An integrated framework for the study of exercise across the postdiagnosis cancer continuum

Exercise plays many important roles across the entire cancer continuum that have been described in previous frameworks. These frameworks, however, have generally provided a simplified description of the roles of exercise postdiagnosis. The modern cancer treatment landscape has become complex and often consists of multiple lines of multimodal treatments combined concurrently and/or sequentially and delivered over many months or years. This complexity requires a more multifaceted and targeted approach to the study of exercise after a cancer diagnosis. Here, we propose a new integrated framework-Exercise Across the Postdiagnosis Cancer Continuum (EPiCC)-that highlights the distinct roles of exercise for disease treatment and supportive care from diagnosis until death. We also propose new terminology to clarify the distinct roles of exercise that emerge in the context of the modern cancer treatment landscape. The EPiCC Framework is structured around multiple sequential cancer treatments that highlight six distinct cancer treatment-related time periods for exercise-before treatments, during treatments, between treatments, immediately after successful treatments, during longer term survivorship after successful treatments, and during end of life after unsuccessful treatments. The EPiCC Framework proposes that the specific roles of exercise as a disease treatment and supportive care intervention will vary depending on its positioning within different cancer treatment combinations. As a cancer treatment, exercise may serve as a "priming therapy", primary therapy, neoadjuvant therapy, induction therapy, "bridging therapy", adjuvant therapy, consolidation therapy, maintenance therapy, and/or salvage therapy. As a supportive care intervention, exercise may serve as prehabilitation, intrahabilitation, interhabilitation, rehabilitation, "perihabilitation", health promotion/disease prevention, and/or palliation. To date, exercise has been studied during all of the cancer treatment-related time periods but only in relation to some cancer treatments and combinations. Moreover, fewer studies have examined exercise across multiple cancer treatment-related time periods within any cancer treatment combination. Future research is needed to study exercise as a disease treatment and supportive care intervention within and across the distinct cancer treatment-related time periods contained within different cancer treatment combinations. The aim of the EPiCC Framework is to stimulate a more targeted, integrated, and clinically-informed approach to the study of exercise after a cancer diagnosis.

Exercise Across the Phases of Cancer Survivorship: A Narrative Review

Exercise has long been recognized as an important component of treatment for various diseases. However, the benefits and risks of exercise interventions must be carefully evaluated to ensure the former outweighs the latter. As cancer patients undergo diverse treatment modalities with distinct objectives, a systematic approach partitioning the cancer journey into distinct phases is necessary to inform tailored exercise prescriptions. This narrative review summarizes exercise benefits and mechanisms for cancer patients and survivors across four distinct survivorship periods-before surgery, after surgery and before adjuvant treatment, during nonsurgical treatment (adjuvant and neoadjuvant), and during extended survival. In summary, exercise reduces the risks of complications and declines in physical functioning while improving fatigue, quality of life, and the ability to manage treatment effects. Although additional research is warranted, existing evidence is sufficient to integrate exercise into clinical oncology practice and cancer survivorship programs.

Retention rates and reasons for non-retention in exercise oncology trials in the post-treatment phase-a systematic review

PURPOSE

Retention is a key marker of trial success. Poor retention can induce bias, reduce statistical power and minimise the validity of trials. This review examined retention rates in exercise trials in cancer survivors, reasons for non-retention and retention strategies utilised.

METHODS

A systematic review was conducted using a predefined search strategy in EMBASE RCTs, MEDLINE OVID, CINAHL, Web of Science-Core Collection and Cochrane Central Register of Controlled Trials (CENTRAL). The search was conducted on 27/03/2023. Title and abstract screening, full text review and data extraction were completed in duplicate.

RESULTS

Of 17,524 studies identified, 67 trials involving 6093 participants were included. The median overall retention rate immediately post-intervention was 89.85%, range (52.94-100%) and mean 87.36% (standard deviation 9.89%). Trials involving colorectal cancer survivors only had the highest median retention rate (94.61%), followed by breast (92.74%), prostate (86.00%) and haematological cancers (85.49%). Studies involving mixed cancer cohorts had the lowest retention rate (80.18%). The most common retention strategies were wait-list control groups, regular check-ins/reminders and free exercise equipment. Common reasons for non-retention were lost to follow-up, health problems, personal reasons including family/work commitments and travel burden, and disease progression.

CONCLUSIONS

Retention rates in exercise oncology trials are approximately 90% immediately post-interventions. Our previous work highlighted variable suboptimal recruitment rates of median 38% (range 0.52-100%). Recruitment rather than retention should be prioritised for methodology research in exercise oncology.

IMPLICATIONS FOR CANCER SURVIVORS

Optimising the quality of exercise oncology trials is critical to informing high quality survivorship care. PROSPERO registration number: CRD42023421359.

Physical activity for cancer prehabilitation: A scoping review

This scoping review aims to synthesize the current landscape of physical activity in cancer prehabilitation and identify knowledge gaps. We searched MEDLINE, EMBASE, SCOPUS and WEB OF SCIENCE for exercise interventions and observational studies that measured exercise or physical activity before cancer treatment from inception to January 20, 2023. Fifty-one articles from 44 unique studies were reviewed, including 32 intervention and 12 observational studies. Surgery is the only treatment modality that has been investigated. Included studies used heterogeneous exercise interventions and measures for physical activity. Colorectal and other gastrointestinal, lung, and urologic cancers are the most studied cancer types. Exercise intervention in cancer prehabilitation is highly feasible. The evidence for improved fitness, functional, psychosocial, and clinical outcomes is promising yet limited. Although research has increased recently, prehabilitation exercise remains a relatively under-investigated area in oncology. We have provided research directions towards an ideal cancer prehabilitation design in the real-world setting.

Exercise therapy as a digital therapeutic for chronic disease management: consideration for clinical product development

Digital exercise therapies (DET) have the potential to bridge existing care gaps for people living with chronic conditions. Acting as either a standalone, embedded within multi-modal lifestyle therapy, or adjunct to pharmacotherapy or surgery, evidence-based DETs can favorably impact the health of a rapidly growing population. Given the nascent nature of digital therapeutics, the regulatory landscape has yet to mature. As such, in the absence of clear guidelines clinical digital product developers are responsible for ensuring the DET adheres to fundamental principles such as patient risk management and clinical effectiveness. The purpose of this narrative review paper is to discuss key considerations for clinical digital product developers who are striving to build novel digital therapeutic (DTx) solutions and thus contribute towards standardization of product development. We herein draw upon DET as an example, highlighting the need for adherence to existing clinical guidelines, human-centered design and an intervention approach that leverages the Chronic Care Model. Specific topics and recommendations related to the development of innovative and scalable products are discussed which ultimately allow for differentiation from a basic wellness tool and integration to clinical workflows. By embodying a code of ethics, clinical digital product developers can adequately address patients' needs and optimize their own future digital health technology assessments including appropriate evidence of safety and efficacy.

In Vitro and In Vivo Effects of Synthesis Novel Phenoxyacetamide Derivatives as Potent Apoptotic Inducer against HepG2 Cells through PARP-1 Inhibition

To discover potential cytotoxic agents, new semi-synthetic phenoxy acetamide derivatives, compound I and compound II, were synthesized, characterized, and screened for their cytotoxic activity against breast cancer (MCF-7) and liver cancer (HepG2) cell lines. The two compounds were more promising against HepG2 than the MCF-7 cell line according to IC50 values. When tested against the HepG2 cell line, compound I, and compound II both had significantly increased cytotoxic activity when compared to the reference medication 5-Fluorouracil (5-FU), with IC50 values of 1.43 M, 5.32 M, and 6.52 M for compound 1, 5-FU and compound II, respectively. Also, compound I displayed a degree of selectivity towards cancer cells compared to normal cells. Compound I significantly enhanced HepG2 total apoptotic cell death by about a 24.51-fold increase. According to cell cycle analysis, compound I induced the arrest of the cell cycle phases G1/S and blocked the progression of the HepG2 cells. Applying the RT-PCR technique achieved a highly significant upregulation in pro-apoptotic genes. The anti-apoptotic gene was significantly downregulated. There was an intrinsic and extrinsic pathway, but the intrinsic pathway was the dominant one. Tumor growth suppression as measured by tumor weight and volume and other hematological, biochemical, and histopathological analyses confirmed the efficacy of compound I as an anticancer agent in vivo examination. Finally, the molecular docking study revealed that compound I was properly docked inside the binding site of PARP-1 protein with stable binding energies and interactive binding modes. Therefore, compound I shows promise as a selective anti-cancer derivative for the treatment of liver cancer after more investigations and clinical studies. This selectivity is a favorable characteristic in the developing cytotoxic agents for cancer treatment, as it indicates a potential for reduced harm to health tissues.

Exercise improves the outcome of anticancer treatment with ultrasound-hyperthermia-enhanced nanochemotherapy and autophagy inhibitor

It has been shown that exercise has a direct impact on tumor growth along with functional improvement. Previous studies have shown that exercise decreases the risk of cancer recurrence across various types of cancer. It was indicated that exercise stimulates the immune system to fight cancer. Previous study demonstrated that pulsed-wave ultrasound hyperthermia (pUH) combined with PEGylated liposomal doxorubicin (PLD) and chloroquine (CQ) inhibits 4T1 tumors growth and delays their recurrence. In this study, we investigated if the combinatorial treatment with high-intensity interval training (HIIT) combined with pUH-enhanced PLD delivery and CQ improved the outcome. The mouse experiment composed of three groups, HIIT+PLD+pUH+CQ group, PLD+pUH+CQ group, and the control group. HIIT+PLD+pUH+CQ group received 6 weeks of HIIT (15 min per day, 5 days per week) before 4T1 tumor implantation. Seven days later, they received therapy with PLD (10 mg/kg) + pUH (3 MHz, 50% duty cycle, 0.65 W/cm2, 15min) + CQ (50 mg/kg daily). Results showed that HIIT+PLD+pUH+CQ significantly reduced the tumor volumes and brought about longer survival of tumor-bearing mice than PLD+pUH+CQ did. Blood cell components were analyzed and showed that neutrophil and reticulocytes decreased while lymphocytes increased after exercise.

Translating energy balance research from the bench to the clinic to the community: Parallel animal-human studies in cancer

Advances in energy balance and cancer research to date have largely occurred in siloed work in rodents or patients. However, substantial benefit can be derived from parallel studies in which animal models inform the design of clinical and population studies or in which clinical observations become the basis for animal studies. The conference Translating Energy Balance from Bench to Communities: Application of Parallel Animal-Human Studies in Cancer, held in July 2021, convened investigators from basic, translational/clinical, and population science research to share knowledge, examples of successful parallel studies, and strong research to move the field of energy balance and cancer toward practice changes. This review summarizes key topics discussed to advance research on the role of energy balance, including physical activity, body composition, and dietary intake, on cancer development, cancer outcomes, and healthy survivorship.

Harms of exercise training in patients with cancer undergoing systemic treatment: a systematic review and meta-analysis of published and unpublished controlled trials

Background

Exercise is recommended for people with cancer. The aim of this study was to evaluate the harms of exercise in patients with cancer undergoing systemic treatment.

Methods

This systematic review and meta-analysis included published and unpublished controlled trials comparing exercise interventions versus controls in adults with cancer scheduled to undergo systemic treatment. The primary outcomes were adverse events, health-care utilization, and treatment tolerability and response. Eleven electronic databases and trial registries were systematically searched with no date or language restrictions. The latest searches were performed on April 26, 2022. The risk of bias was judged using RoB2 and ROBINS-I, and the certainty of evidence for primary outcomes was assessed using GRADE. Data were statistically synthesised using pre-specified random-effect meta-analyses. The protocol for this study was registered in the PROESPERO database (ID: CRD42021266882).

Findings

129 controlled trials including 12,044 participants were eligible. Primary meta-analyses revealed evidence of a higher risk of some harms, including serious adverse events (risk ratio [95% CI]: 1.87 [1.47-2.39], I2 = 0%, n = 1722, k = 10), thromboses (risk ratio [95% CI]: 1.67 [1.11-2.51], I2 = 0%, n = 934, k = 6), and fractures (risk ratio [95% CI]: 3.07 [3.03-3.11], I2 = 0%, n = 203, k = 2) in intervention versus control. In contrast, we found evidence of a lower risk of fever (risk ratio [95% CI]: 0.69 [0.55-0.87], I2 = 0% n = 1109, k = 7) and a higher relative dose intensity of systemic treatment (difference in means [95% CI]: 1.50% [0.14-2.85], I2 = 0% n = 1110, k = 13) in intervention versus control. For all outcomes, we downgraded the certainty of evidence due to imprecision, risk of bias, and indirectness, resulting in very low certainty of evidence.

Interpretation

The harms of exercise in patients with cancer undergoing systemic treatment are uncertain, and there is currently insufficient data on harms to make evidence-based risk-benefits assessments of the application of structured exercise in this population.

Funding

There was no funding for this study.

The Mediterranean Lifestyle to Contrast Low-Grade Inflammation Behavior in Cancer

A healthy diet and an active lifestyle are both effective ways to prevent, manage, and treat many diseases, including cancer. A healthy, well-balanced diet not only ensures that the body gets the right amount of nutrients to meet its needs, but it also lets the body get substances that protect against and/or prevent certain diseases. It is now clear that obesity is linked to long-term diseases such as heart disease, diabetes, and cancer. The main reasons for people being overweight or obese are having bad eating habits and not moving around enough. Maintaining weight in the normal range may be one of the best things to avoid cancer. It has been scientifically proven that those who perform regular physical activity are less likely to develop cancer than those who lead a sedentary lifestyle. Moving regularly not only helps to maintain a normal body weight, avoiding the effects that favor tumor growth in overweight subjects, but also makes the immune system more resistant by counteracting the growth of tumor cells. Physical activity also helps prevent cardiovascular and metabolic diseases. In this review, it is highlighted that the association between the Mediterranean diet and physical activity triggers biological mechanisms capable of counteracting the low-grade chronic inflammation found in patients with cancer. This assumes that healthy lifestyles associated with cancer therapies can improve the expectations and quality of life of cancer patients.

Designing, analyzing, and interpreting observational studies of physical activity and cancer outcomes from a clinical oncology perspective

Observational studies may play an important role in evaluating physical activity (PA) as a cancer treatment; however, few studies have been designed, analyzed, or interpreted from a clinical oncology perspective. The purpose of the present paper is to apply the Exercise as Cancer Treatment (EXACT) Framework to assess current observational studies of PA and cancer outcomes from a clinical oncology perspective and provide recommendations to improve their clinical utility. Recent systematic reviews and meta-analyses of over 130 observational studies have concluded that higher prediagnosis and postdiagnosis PA are associated with lower risks of cancer-specific and all-cause mortality. Most of these studies, however, have: (a) included cancer patients receiving heterogeneous treatment protocols, (b) provided minimal details about those cancer treatments, (c) assessed PA prediagnosis and/or postdiagnosis without reference to those cancer treatments, (d) reported mainly mortality outcomes, and (e) examined subgroups based on demographic and disease variables but not cancer treatments. As a result, current observational studies on PA and cancer outcomes have played a modest role in informing clinical exercise trials and clinical oncology practice. To improve their clinical utility, we recommend that future observational studies of PA and cancer outcomes: (a) recruit cancer patients receiving the same or similar first-line treatment protocols, (b) collect detailed data on all planned and unplanned cancer treatments beyond whether or not cancer treatments were received, (c) assess PA in relation to cancer treatments (i.e., before, during, between, after) rather than in relation to the cancer diagnosis (i.e., various time periods before and after diagnosis), (d) collect data on cancer-specific outcomes (e.g., disease response, progression, recurrence) in addition to mortality, (e) conduct subgroup analyses based on cancer treatments received in addition to demographic and disease variables, and (f) interpret mechanisms for any associations between PA and cancer-specific outcomes based on the clinical oncology scenario that is recapitulated rather than referencing generic mechanisms or discordant preclinical models. In conclusion, observational studies are well-suited to contribute important knowledge regarding the role of PA as a cancer treatment; however, modifications to study design and analysis are necessary if they are to inform clinical research and practice.